Food security may be less of an issue for urban dwellers than previously thought.

Take the case of 70-year-old Andy Hoi-Csiu Chan. He tends bamboo, peonies, watermelon, eggplants and other vegetables in his Chicago backyard. Chan, an immigrant from China who teaches traditional brush painting at his Chinatown studio, started his garden about 12 years ago.

"I love to see that they grow," he said. "Many, many friends to come to my house and I cook for them." Even in January, Chan keeps a stock of vegetables from his garden grown the previous summer.

Chan is a member of a significant and previously undocumented population of Chicago urban farmers. Though Chan said he wasn't aware of it, researchers at the University of Illinois recently discovered that many of his neighbors, especially those of Chinese origin, are also enjoying the fruits and vegetables of backyard gardening.

Based on the number of newly located food-producing backyards, Chicagoans may be more protected from future climate-induced food shortages and food price swings than some researchers have thought. The study sheds more light on food security issues that could arise as more people around the world are moving to cities.

Using satellite images from Google Earth, researchers Jon Taylor and Sarah Taylor Lovell have produced a new, more accurate study of Chicago's urban agriculture sites, revealing a significant number of home gardeners like Chan.

Taylor, a doctoral candidate at the University of Illinois' Department of Crop Sciences, and Taylor Lovell, an assistant professor in the same department, discovered that residential gardens accounted for almost three-fourths of the total area of Chicago's urban agriculture sites.

Taylor and Taylor Lovell also found that earlier records of Chicago's community gardening sites, mostly provided by local nongovernmental organizations, were misleading. Among the 1,236 sites listed as community gardens, only 13 percent were actually growing food.

Hunting vegetables by satellite
The project began as an attempt to locate community gardens for use as research sites. Using the only lists available, Taylor and his fellow researchers learned that many of Chicago's recorded community gardens were actually ornamental gardens, playgrounds or parks.

In an attempt to identify workable research sites, Taylor and his fellow researchers turned to satellite images on Google Earth.

"We noticed that we could actually look in people's backyards and identify the larger sites of food production on private lots," he said. "I was surprised by the size of some of the backyard gardens."

The researchers decided to manually survey the quantity and area of Chicago's urban agriculture. Taylor examined hundreds of high-resolution aerial images of Chicago's neighborhoods on Google Earth. By searching for signs of vegetation, raised beds and tilled earth, he was able to mark the location and size of both community and residential gardens.

To account for the Chicago area's 234 square miles, Taylor spent about 400 hours in front of a computer screen and visited almost 200 undocumented community gardens to confirm his findings.

Ultimately, Taylor was able to identify 4,648 urban agriculture sites in the city of Chicago, with a total production area of 315,958 square yards -- enough garden sites to fill almost 50 football fields. Most of these sites -- 86 percent -- were identified as food-producing residential gardens.

Taylor believes his official report of about 120,000 residential garden sites is a conservative number. Google Earth's satellite images aren't detailed enough to show smaller gardens, he said. "I think people will find a way to garden, no matter how small the space is."

"When I was looking at the images, I kept seeing these curious structures in backyards," he said. "I saw them mostly in Chinatown and also in the Bridgeport neighborhoods, and both of those neighborhoods have large Chinese-origin populations."

Taylor decided to visit Chinatown, and while walking up and down alleys behind residences, he discovered the structures were trellises, made of pieces of pipe and wood, supporting vining crops like melons and other gourds. After examining their data, Taylor and Taylor Lovell concluded that many of Chicago's residential gardens are tended by immigrants like Chan, living in the city's Chinatown area.

"Two neighborhoods on the near south side, Chinatown and Bridgeport, appear to be home garden hot spots for demographic and cultural reasons," said the final report, published in August in the scientific journal Landscape and Urban Planning.

Chinatown and part of Bridgeport were classified as "food deserts" in a 2011 report compiled by the Chicago-based Mari Gallagher Research and Consulting Group. Taylor thinks that, to some extent, home gardens help compensate for the lack of quality, culturally appropriate foods in this area.

"That's a really important component of food security," he said. "We often think about food security just having enough food to eat, but it's also about having the right kinds of food."

The bounty of immigrants
Chicago neighborhoods with significant populations of European immigrants, like Dunning and Norwood Park, also had high concentrations of residential gardens.

As of yet, there are no significant data to support the supposition that certain recent immigrant groups are more likely to have home gardens than others, said Alicia Woodbury, a doctoral student at Arizona State University's School of Social Transformation, who researches inequalities in food and agricultural systems.

"What I do think is true, based on my own research, is that many recent immigrant groups are more likely to have agricultural knowledge than the average American who is just getting involved with gardening for the first time," she said. "In many cases, this is because they were farmers in their countries of origin."

In light of these findings, Taylor believes the many recently discovered home gardens should be acknowledged as an asset to Chicago's urban agriculture. Communities can use this and similar research to promote and assist backyard gardeners like Chan.

"People are doing an incredible job, basically on their own, and sometimes with few resources," Taylor said. "I think that if there were ways to augment those resources, that would be terrific."

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